Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Therapy for severe myocardial ischemia/reperfusion sometimes necessitates intermittent positive pressure ventilation, which may impair left ventricular function by reduction of ventricular loading. It is unknown today whether positive airway pressure also affects contractile force after myocardial ischemia/reperfusion. The authors tested whether positive end-expiratory pressure (PEEP) impairs myocardial contractility in acute ischemic heart failure. ⋯ Now, both PRSW (P < 0.05, PEEP 5 cm H2O) and E(es) (P < 0.05, PEEP 10 cm H2O) improved upon ventilation with PEEP. In our model, the administration of PEEP impaired global left ventricular function before and after myocardial ischemia/reperfusion. The observed impairment is not attributable to compromised contractility.
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The differential effects of the use of high or low oxygen levels during resuscitation on the neonatal liver are unknown. We compared the hepatic hemodynamics and oxygen metabolism in hypoxic newborn piglets resuscitated with 21% or 100% oxygen. Twenty-seven piglets (age, 1-3 days; weight, 1.5-2.0 kg) were acutely instrumented to measure cardiac output, hepatic artery, and portal venous blood flows (hepatic artery flow index [HAFI] and portal venous flow index [PVFI], respectively). ⋯ The plasma lactate concentrations increased in both groups with hypoxia and were not different during reoxygenation between the group administered with 21% oxygen and the group administered with 100% oxygen. The hypoxic neonatal liver has reduced hepatic blood flow but has relatively preserved HAFI, and oxygen consumption recovered similarly on reoxygenation with 21% and 100% oxygen. The increased oxygen extraction during hypoxia normalized in 21% but reduced in 100% reoxygenation, with no differences in plasma lactate concentrations.